Who is making the sub frame collars for the SC400 ???

 

I believe Battle Version does.

 

What is a sub frame collar?

 

I think the sc300 and sc400 uses the same rear subframe, so the PBM subframe/diff collars should work. Instead of a full on bushing replacement like what battle version sells, the PBM's just go in between the chassis/frame and the subframe to keep the bushing from moving. I think their set included 2 collars for the front subframe bushings and 2 for the diff ear bushings. super simple to install as well, just lower the subframe and diff down a bit and slip em in.

 

PBM no longer sells them, I'd go with what battleversion has or a few japanese brands exist but battleversion is easy easy.